@article{fdi:010049518,
  title = {{L}ongitudinal zonation of macroinvertebrates in an {E}cuadorian glacier-fed stream : do tropical glacial systems fit the temperate model ?},
  author = {{J}acobsen, {D}. and {D}angles, {O}livier and {A}ndino, {P}. and {E}spinosa, {R}. and {H}amerlik, {L}. and {C}adier, {E}ric},
  editor = {},
  language = {{ENG}},
  abstract = {1. {T}he ecology of glacier-fed streams at temperate latitudes has been intensely studied in recent years, leading to the development of a well-validated conceptual model on the longitudinal distribution of macroinvertebrate communities downstream of the glacier margin ({F}reshwater {B}iology, 2001a; 46, 1833). {H}owever, to our knowledge, the ecology of tropical glacier-fed streams has not yet been studied. 2. {W}e sampled benthic macroinvertebrates and measured environmental variables at nine sites between 4730 and 4225 m altitude along a 4.3 km stretch of a glacier-fed stream 40 km south of the equator in the {E}cuadorian {A}ndes. {O}ur goal was to study the longitudinal distribution of the fauna in relation to environmental factors and to compare this with the conceptual model based on temperate-arctic glacier-fed streams. 3. {T}otal density of invertebrates differed considerably at the two highest altitude sites; 4600 m-2 at a pro-glacial lake outlet and only 4 m-2 at a site originating directly from the glacier snout. {O}therwise, there was a downstream decrease in density to about 825 m-2 at the three lowest sites. {T}axon richness increased with distance from the glacier, very similar to the pattern predicted. {A} total of 28 taxa were collected; two at the glacier snout, seven at the nearby pro-glacial lake outlet, 13 at site 2 (< 400 m from the glacier) and 20 at the lowest sites. 4. {T}he numerical percentage of {C}hironomidae ({D}iptera) decreased downstream from 100 to 44%. {T}he subfamily {P}odonominae was numerous at the highest sites but became much less important further downstream. {T}he {O}rthocladiinae were important both in numbers and species at all sites, while {D}iamesinae were numerous only in the middle of the reach studied and were completely absent from the upper three sites. {T}he limited importance of the {D}iamesinae, and its replacement by {P}odonominae, is different from the pattern typically observed in north-temperate glacier-fed streams. {T}his could be because of the fact that the genus {D}iamesa is missing from the {N}eotropics. 5. {S}tream temperature and channel stability explained most of the variability in faunal composition and richness, supporting the model. {S}tability increased systematically downstream while temperature did not. {S}urprisingly, no classical kryal zone ({T}-max < 4 degrees {C}) was found, as even the site closest to the glacier snout (50 m) had a {T}-max of 15 degrees {C} and no site had {T}-max < 8 degrees {C}. {W}e propose that this might be a general feature of equatorial glacial streams.},
  keywords = {community composition ; fauna ; {H}igh {A}ndes ; physical stability ; water ; temperature},
  booktitle = {},
  journal = {{F}reshwater {B}iology},
  volume = {55},
  numero = {6},
  pages = {1234--1248},
  ISSN = {0046-5070},
  year = {2010},
  DOI = {10.1111/j.1365-2427.2009.02348.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049518},
}